UNIVERSITY  OF  CALIFORNIA  Agricultural  experiment  Station 

College  of  Agriculture  e.  w.  hilgard.  director 

BERKELEY,  CALIFORNIA 


CIRCULAR  No.  4. 

(June,  1903.) 


ANTHRAX 

By  ARCHIBALD  R.  WARD, 

Veterinarian  and  Bacteriologist. 


Synonyms. — Anthrax  is  also  known  by  the  following  names:  Charbon, 
Splenic  fever,  Splenic  apoplexy,  Malignant  carbuncle,  Malignant  pus- 
tule, Woolsorters'  disease. 

Animals  Affected. — The  disease  attracts  attention  chiefly  as  a  cattle 
disease,  but  it  may  be  contracted  by  man  and  most  of  the  domestic 
animals,  such  as  horses,  sheep,  swine,  and  dogs. 

Conditions  Under  Which  the  Disease  is  Liable  to  Break  Out. — Anthrax 
is  caused  by  the  presence  of  bacteria  in  the  blood,  which  generally  gain 
access  to  the  body  from  the  soil  with  the  food.  Anthrax  germs  thrive 
and  exist  indefinitely  in  damp,  heavy,  undrained  swampy  land  having  a 
high  water-table  or  subject  to  periodical  flooding.  River-bottom  land, 
dried  lake  basins,  or  deltas  are  characteristic  of  the  localities  infected  with 
anthrax.  The  disease  is  most  apt  to  occur  during  hot,  dry  weather. 
At  such  times  cattle  are  frequently  pastured  upon  low  lands  which  may 
not  be  desirable  nor  available  for  use  in  the  winter.  In  Louisiana  the 
disease  is  spread  by  the  bite  of  large  flies,  causing  swellings  and  sores 
on  the  skin. 

Symptoms. — The  disease  kills  very  quickly,  sometimes  in  only  a  few 
hours  after  sickness  is  noticed.  There  is  high  fever  with  the  accom- 
panying quickened  breathing,  hot  horns  and  ears.  Great  variation  in 
behavior  is  noted  in  different  affected  animals.  Sometimes  there  is 
nervous  excitement;  sometimes  great  depression.  The  urine  may  be 
dark  and  the  dung  may  be  bloody  or  streaked  with  blood.  The  nostrils, 
tongue,  etc.,  may  be  darkened  in  color.  In  some  cases  the  disease  affects 
the  skin,  producing  swellings  that  do  not  crackle  when  touched. 


—  2  — 

Pigs  affected  by  eating  infected  meat  generally  contract  the  disease 
in  the  throat  and  intestines.  There  is  marked  swelling  of  the  throat, 
interfering  with  breathing;  diarrhea  and  a  darkened  color  of  the  tongue. 

In  man  the  disease  occurs  first  as  a  malignant  carbuncle,  generally 
traced  to  some  slight  wound,  incurred  while  skinning  an  infected 
carcass.  Later  there  may  be  great  swelling  of  the  affected  part,  with 
possible  fatal  termination. 

Post-Mortem  Appearances. — The  blood  is  usually  dark  in  color  and 
tarry  in  consistency.  The  spleen  (milt)  is  always  distended  with  a 
bloody,  pulpy  mass.  There  is  frequently  found  under  the  skin,  and 
around  some  of  the  internal  organs,  a  gelatinous,  yellowish,  transparent 
substance,  which  may  be  streaked  with  blood.  It  is  exceedingly  dan- 
gerous to  tamper  with  the  carcass  of  an  animal  dead  of  anthrax,  unless 
the  hands  are  protected  by  rubber  gloves. 

Disposal  of  the  Dead. — Burning  is  the  most  desirable  means  of  dis- 
posal. If  burial  is  necessary  it  is  exceedingly  desirable  that  the  carcasses 
of  animals  dead  of  anthrax  be  buried  without  being  open  to  the  air  for 
any  length  of  time.  A  spot  should  be  selected  in  a  locality  where  there 
is  no  danger  of  contaminating  a  stream  of  water.  Animals  grazing  over 
the  grave,  years  after  burial,  are  liable  to  contract  the  disease.  Sur- 
rounding the  carcass  with  lime  is  desirable.  Hogs  will  die  if  fed  with 
the  carcasses  of  animals  dead  of  anthrax. 

Differences  Between  Anthrax  and  Texas  Fever. — To  the  untrained 
observer  there  are  some  similarities  in  the  symptoms  and  internal 
alterations  of  Texas  fever  and  anthrax,  and  in  consequence  some  con- 
fusion exists.  In  both  cases  there  is  fever  and  there  may  be  dark-colored 
urine.  In  both  the  spleen  is  enlarged.  Here  the  identity  ceases. 
Below  are  tabulated  some  of  the  more  prominent  differences  between 
them  (From  Law,  Veterinary  Medicine,  Vol.  4): 


Texas  Fever. 
Not  restricted  to  swampy  lands  only. 


Attacks  bovine  animals  only. 

Sucking  calves  nearly  immune. 

Mucosae  become  increasingly  pale ;  yellow 
in  violent  attacks. 

Blood  becomes  increasingly  tbin  and  watery. 

Bile  abundant,  tbick  and  tarry. 


Anthrax. 
Prevails    in    ricb,    swampy,    impermeable 
soils ;    not    permanently  implanted    on 
open,  well-drained  land. 

Attacks    mammals,    generally,    especially 
berbivora. 

Sucking  calves  susceptible. 

Mucosae  dusky  brownisb  red ;  not  pallid  nor 
yellow. 

Blood  becomes  tbick,  tarry,  not  watery. 

Bile  fluid. 


It  is  an  unfortunate  fact  that  information  concerning  Texas  fever  has 
not  been  sufficiently  disseminated  among  stockmen,  which  has  resulted 
in  undesirable  confusion.     The  present  writer   holds   the   belief   that 


—  3  — 

many  cases  of  Texas  fever  in  the  past  have  been  called  anthrax,  and 
that  future  investigations  will  show  the  regions  infected  with  anthrax  to 
be  much  more  restricted  than  is  now  generally  believed  to  be  the  case. 

Vaccination  for  Anthrax. — There  is  on  the  market  a  vaccine  by  which 
it  is  claimed  a  mild  attack  of  anthrax  may  be  induced,  with  the  result 
that  the  animal  is  protected  from  a  natural  attack.  Its  use  is  much  more 
dangerous  than  the  common  practice  of  vaccinating  for  blackleg,  and 
vaccination  for  anthrax  should  be  practiced  only  with  great  caution. 
There  is  need  of  its  use  only  upon  animals  actually  pastured  upon 
swampy  lands,  which  are  known  beyond  a  doubt  to  be  infected  with 
anthrax.  Do  not  vaccinate  for  anthrax  merely  because  its  outbreak  is 
dreaded,  for  some  risk  of  actually  introducing  the  disease  is  incurred 
thereby.  Anthrax  originates  in  animals  pastured  on  low,  swampy  land 
and  is  not  usually  immediately  communicated  to  other  animals  from 
them  unless  there  are  carbuncles  present  on  the  surface  of  the  body. 
Animals  may  contract  the  disease  on  infected  ground,  and  the  disease 
break  out  after  they  have  been  driven  elsewhere  and  mixed  with  other 
cattle,  without  the  others  contracting  the  disease. 

Anthrax  is  an  entirely  different  disease  from  blackleg,  and  conse- 
quently blackleg  vaccine  is  useless  for  preventing  anthrax,  and  vice  versa. 

Treatment  Unsatisfactory. — Anthrax  does  not  usually  yield  to  medici- 
nal treatment. 


SACRAMENTO '. 
W.    SHANNON,        •       -      SUPT.    STATE    PRINTING. 
1903. 


